The present invention relates to an apparatus and a method for displaying document data on a display. More particularly, the present invention relates to an apparatus and a method for displaying document data larger than a document displaying area of a display.
Along with popularization of computer, letters and reports conventionally read on paper documents have now been read more often as electronic documents such as electronic mail and electronic reports on displays of computers. Because of various factors including the screen size and resolution, what is displayed on a display of a computer is not always more legible than paper documents, but chances of reading documents on a display tend to increase further hereafter. There is therefore a demand for a method for more legible display.
In the conventional methods of display of a document display apparatus, methods for displaying a document in an area on the display and then displaying the next document include the scrolling method and the screen switchover method. The scrolling method is to display sequentially the following documents on the screen while acting on a scroll key, and is widely applied. The screen switchover method consists of rewriting an entire display area into the next document and corresponds to paging in the case of a paper document.
In the conventional scrolling method, however, it is virtually impossible to read the document during scrolling, and upon completion of scrolling, the last read portion before scrolling must be searched for, leading to an inconvenience of temporary interruption of reading operation. For screen switchover method cannot be a sufficiently satisfactory method in that the next or the preceding document cannot be compared on the same screen shortly before and after rewriting. It is therefore inconvenient when continuously reading a long electronic document, resulting in a lower reading efficiency and a serious fatigue.